1. Field of the Invention
The present invention relates to a roll crusher for breaking concrete, asphalt and natural stone into lumps of predetermined size. More particularly, the present invention relates to a roll crusher for breaking scrap pieces of concrete, asphalt, etc. produced during repair, reconstruction and so forth of roads, concrete structures, etc. for the purpose of recycling, or for crushing natural stone into lumps of predetermined size.
2. Discussion of Related Art
A large amount of scrap concrete and asphalt is produced as industrial waste by reconstruction of buildings and road repairing work. These scrap pieces have heretofore been subjected to reclaiming disposal. However, the number of reclaiming disposal sites is decreasing because of environmental destruction and other problems. Therefore, it is desired that scrap concrete and asphalt be reused. Under these circumstances, a breaking machine has recently been developed which is designed to crush and break scrap pieces of concrete or the like into lumps of predetermined size and to crush them with rotating rotary teeth with a view to recycling (e.g. Japanese Patent Application Unexamined Publication (KOKAI) No. Hei 5-09282).
The inventors of the present invention also proposed roll crushers having rotating rotary teeth (e.g. Japanese Patent Application Unexamined Publication (KOKAI) No. Hei 11-319596 and Japanese Patent Application No. Hei 11-143936).
However, because scrap pieces of concrete are irregular in size and thickness, if cast into a breaking machine, they are not readily crushed into lumps of appropriate size. During crushing, concrete scrap pieces may be caught in the gap between the rotating rotors, causing the rotors to become unable to rotate. In addition, the crushing teeth are worn by pieces of concrete thrown in, and breaking teeth provided on the outer peripheries of the rotors wear out at a high rate. Consequently, it is necessary to replace the rotors or to subject them to build-up welding. This causes costs to increase.
The conventional crushers use breaking teeth having a single function, which are disposed on the outer periphery of a cylindrical rotor body. This may cause clogging with the material. That is, because breaking teeth having the same shape and the same function are simply arranged side by side, the teeth may turn free without biting into material when its shape is close to that of a large ball, for example.
The present invention was made in view of the above-described problems with the prior art. Accordingly, the present invention attains the following objects.
An object of the present invention is to provide a roll crusher that is unlikely to become unable to rotate regardless of the shape and size of material to be crushed.
Another object of the present invention is to provide a roll crusher capable of automatically moving material cast therein to a crushing area without guiding it.
A further object of the present invention is to provide a roll crusher capable of crushing material with different crushing functions.
A further object of the present invention is to provide a roll crusher having a fixing mechanism capable of firmly fixing breaking teeth to a rotor body.
To attain the above-described objects, the present invention provides a roll crusher having a plurality of kinds of crushing teeth for crushing a material to be crushed on the outer periphery of a rotor driven to rotate. The roll crusher includes a cylindrical rotor body and a plurality of breaking teeth for crushing the material mainly by a wedge effect. The breaking teeth are installed on the outer periphery of the rotor body. Each breaking tooth has a pair of wedge surfaces contiguous to each other with an angle converging in a rotational direction. A plurality of compression teeth for crushing the material mainly by a compressive effect are installed on the outer periphery of the rotor body. Each compression tooth has a plane portion. Further, a plurality of cutting teeth for crushing the material mainly by cutting are installed on the outer periphery of the rotor body. Each cutting tooth has a cutting edge.
The breaking teeth, the compression teeth and the cutting teeth are preferably different in the radial height from the outer peripheral surface of the rotor body.
In addition, the present invention provides a roll crusher having a plurality of kinds of crushing teeth for crushing a material to be crushed on the outer periphery of a rotor driven to rotate. The roll crusher includes a cylindrical rotor body and a plurality of breaking teeth for crushing the material mainly by a wedge effect. The breaking teeth are installed on the outer periphery of the rotor body. Each breaking tooth has a pair of wedge surfaces contiguous to each other with an angle converging in a rotational direction. A plurality of crushing teeth are installed on the outer periphery of the rotor body. The crushing teeth are lower than the breaking teeth in the radial height from the outer peripheral surface of the rotor body. A crushing chamber is open at a portion thereof directly above the rotor body so that the material to be crushed is loaded onto the outer peripheral surface of the rotor body.
The term xe2x80x9ccrushing teethxe2x80x9d means teeth for crushing mainly by cutting-off, crushing by bending, compressive crushing, and crushing by cutting away. It should be noted that in the case of a roll crusher having a plurality of rotor bodies, the crushing chamber may be open at a portion thereof directly above only one of the rotor bodies.
In addition, the present invention provides a roll crusher having a plurality of kinds of crushing teeth for crushing a material to be crushed on the outer periphery of a rotor driven to rotate. The roll crusher includes a cylindrical rotor body driven to rotate. The rotor body has breaking tooth fixing holes radially extending therethrough. The roll crusher further includes a plurality of breaking teeth for crushing the material mainly by a wedge effect. The breaking teeth have insert portions inserted and fixed in the breaking tooth fixing holes, respectively. Each breaking tooth has a pair of wedge surfaces contiguous to each other with an angle converging in a rotational direction. Breaking tooth mounting cotters are installed between the insert portions of the breaking teeth and the side walls of the breaking tooth fixing holes, respectively. The roll crusher further includes cotter fixing members for immovably fixing the breaking tooth mounting cotters.
The roll crusher may further include engagement portions formed in the breaking tooth fixing holes for engagement with the cotter fixing members and bolts for integrally connecting the cotter fixing members and the breaking tooth mounting cotters.
The above and other objects, features and advantages of the present invention will become more apparent from the following description of the preferred embodiments thereof, taken in conjunction with the accompanying drawings.